In order to make next generation of devices the silicon industry must aggressively reduce the thickness of SiO2 or SiOxNy gate dielectrics to approximately 1 nm. Such small gate oxide thickness in ultra-large-scale-integrated circuits (ULSICs) and VLSI have negative consequences. Namely, reduced oxide reliability, lower breakdown strength and higher leakage tunneling currents. These limitations put extreme restrictions on conventional field effect transistor (FET) scalability. To solve the ‘gate oxide problem’ alternative gate oxides with high-k dielectric constant have been tried. However most high-k dielectrics found are amorphous and lack the required valence and conduction band offsets when hetero-junctions with Si are formed. Furthermore, the interface quality of high-k/Si junctions is automatically rougher than the simple native SiO2/Si system.
One of the other prior art techniques included sputtering which resulted in polycrystalline form and that is not suitable for ULSICs or VLSI.
Other existing solutions include the fabrication of a different type of FET, called a FinFET, which is a double or even triple vertical gate FET. This technology requires the use of high quality silicon-on-insulator (SOI) technology. Typically, high quality SOI substrates are formed via the SIMOX process, where oxygen is implanted through the surface of a Si wafer to an appropriate depth and thickness. The resulting defective top most Si layer is subsequently repaired to high mobility silicon via extensive thermal annealing processes.
Another potential use of developing crystalline oxides, nitrides and phosphides is in the area of optoelectronics. Communication networks increasingly rely upon fiber optics for high-speed, low cost transmission. For this, efficient and inexpensive electrically driven planar photonic devices operating at fiber communication wavelengths are needed.
Accordingly, there is a need for materials which can be relatively easily integrated with Si-based electronics manufacturing. Development of such material can also lead to reduction of manufacturing costs. Moreover, there is a need in the industry to design devices with desired wavelength.